I cut my cats out and had the Computers O2 sensor signal removed. I put my Hypertech tuner on and off several times then took it in to chevy (for other reasons) and now my check engine light comes with the DTC P2A04. When Chevy flashes a Computer does it go back to Stock? Do I need to get the O2 Sensors deleted again? What do you think my problem is? Thanks.

 

Don't let Chevy flash your computer if you have a tune!

That being said, the P2A04 is a newer code on '05's that needs to be deleted when the cats are removed. Make sure it's on your "ignore" list. I found that info using search in here...